The theory was supported by finding the same rocks and fossils in western Europe and the eastern North America. There are also similar fossils on the western coast of Africa and the eastern South America. The shapes of these continents nearly fits together. The theory was plausible (believable), but there was no known mechanism to drive these great movements. This problem was later solved by plate tectonics.

↑The heat is caused by a combination of the slow cooling of the Earth from its early high temperature, and heat released by the disintegration of radioactiveisotopes in the Earth. See discussion in Age of the Earth.